Still hearing deleted audio

[pwnified]

Thats what I dont understand, the high impedance signal never travels next to the output signal, unless the design is really bad internally. The signal traveling from the iRig to the iPhone is fairly low impedance (between 200 and 1000 ohms). Is it possible this is where the crosstalk is occurring?

BTW jogren I finally grabbed some 102's from Radio shack, overloaded now with work but eventually I'll get some time to try your design

[jorgren]

Hey pwnified, I hope it performs nicely for you! I don't know if I mentioned this, but I put the JFET inside the guitar (1/4") plug, and it fits pretty easily. I had to wear glasses for the job though.

Yeah, I don't see any obvious reason the iRig may have crosstalk, nor any obvious difference from my design, so I really do need to test mine for that, when, as you, I get a free moment. Peavey claims

"AmpKit Link is a powered device with circuitry that virtually eliminates feedback."

I don't know specifically what this means, but it's intriguing. Maybe a cancellation circuit?

jkevinwolfe, it sounds like you're doing the right experiments to minimize headphone-to-mic bleed. Best case (with the large cans), would you say it's near zero? That gives us a reference point for the quality of the isolation inherent to the earbud jack itself.

[jkevinwolfe]

Jorgen,

At what I'd consider a normal working volume level for the large muffed cans, there is a tiny bit of bleed from the phones through a blue yeti. With the output volume of the track up to +12 and the master output up to +12, this bleed is not showing at all on the DAW output meters. By contrast, in ear buds are moving the bottom bar on the output meter.

If I drop the rhythm track from the mix, the bleed recorded through the cans is low enough that it probably wouldn't be noticed even in an acoustic mix. The bleed from the buds would be noticed in the same mix.

This bleed seems to be mostly organic, but when I step back four feet from the mic it's still there to some degree. So it appears that there could be bleed in the audio coming out of the iPad. I tried this with the built in mic and earphone jack as well and I'm getting bleed from them at four feet back too. That would seem that there's electronic bleed from both the jack and the USB port audio.

[pwnified]

Besides "Over the air", there might be another form of crosstalk worth considering. Remember making those communicators as a kid with 2 coffee cans and a string? Same principle, the transient sound is traveling down the wire physically vibrating the wire itself, and on the apple headset, since the mic is right on the wire, with almost no mass it is free to vibrate and transfer the energy (being a highly sensitive mic and all). This doesn't explain the iRig problem, but might be a factor with the apple headset.

[hp sudon]

hey pwnified, I had the same problem with hearing deleted audio today-- doing the flush cache thing fixed it, but I noticed it after I deleted unused regions and then made mixdowns of single tracks to re-import into DAW. I don't know if it will help but this is pretty much what I remember doing up to the point that it happened: (I don't if doing this will duplicate it though)-

1- After recording 2 tracks of audio with multiple punch ins-- I deleted unreferenced regions via wifi using safari.
2- Mixed down Track 1, with track 2 muted.
3- imported the mix of track 1 into an empty track
4- copied the imported track and pasted into another empty track
5- muted all of the tracks except track 2, then mixed down track 2
6- imported the mix of track 2 into an empty track
7- copied that imported track and pasted into another empty track

AT this point was when I noticed a sound (which was from track 2) coming into the audio, so I muted all of the tracks and the sound was still there, just a short half second or so of audio somewhere in the middle of the song, but I can't verify if it wasn't already there before step 7.

Anyways-- in case you're wondering why I was pasting copies of the same track into other tracks, it's a primitive way to create the delay and chorus effect.

[pwnified]

Thanks for the clear explanation, I'm still looking into it. but this gave me some clues.

[Honeycroft]

I got a Bleeder on a guitar track. Even when I delete all tracks it's still there. I'll try the rename song flush out method an report back.